<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>绝对定位</title>
  <style>
    div{
      width: 100px;
      height: 100px;
      border:1px solid red;
    }
    #D1{
position: absolute;
    right: 0;
      bottom: 0;
      }
    #big{
        width: 200px;
        height: 200px;
        background-color: green;
        margin: 50px 0 0 50px;
        /*参照物*/
        position: relative;
    }
    #big>div{
        width: 100px;
        height: 100px;
        background-color: blue;
        margin: 50px 0 0 50px;

    }
    #big>div>div{
        width: 50px;
        height: 50px;
        background-color: yellow;
       position: absolute;
        left: 0;
        top: 0;

    }
  </style>
</head>
<body>
<div id="big">
    <div>
        <div></div>
    </div>
    </idv>
</div>
<div id=" D1">div1</div>
<div id="D2">dIV2</div>
</body>
</html>